There is known an electrolytic cell useful for producing ozone, which cell contains an inert anode such as an inert glassy carbon, lead dioxide or platinum anode. For the cathode, this cell employs an air cathode for reducing oxygen. The electrolyte can be strongly acidic, e.g., contain tetrafluoroborate ions typically contributed by tetrafluoroboric acid at a 48 weight percent strength or more. Such an electrochemical cell for generating ozone has been described in U.S. Pat. No. 4,541,989.
It has also been known to operate fuel cells using an aqueous electrolyte, with the cell using oxygen or air as oxidant. The cell may contain electrodes that are prepared with platinum black utilizing polytetrafluoroethylene as binding agent. Such fuel cells have been discussed for example in Journal of the Electrochemical Society, Volume 112, No. 2, pages 117-124.
There is still however, a need for electrodes serving as air cathodes for reducing oxygen, which cathodes can withstand strong electrolyte in cathode operation at high current density. For effective operation, these cathodes need to offer extended useful life. Yet, the cathodes should be economical to prepare and employ. They could, thus, not only efficiently employ costly substance such as platinum black, but also be utilized in strongly acidic environment.